Calling mechanism for telephone-exchanges



F. A. LUNDQUIST. C ALLING MECHANISM FOR TELEPHONE EXCHANGES.

APPLICATION FILED MAR. 11. I918.

Patented Jan. 13, 1920.

3 SHEEfSSHEET I- F. A. LUNDQUIST. CALLING MECHANISM FOR TELEPHONEEXCHANGES.

APPLICATION FILED MAR. 11. 1918.

Patented Jan.13,l920.

3 nm. a X a W UE 8 .n r .8 QNQ. m wm WM mm m an 4 .1 a QM m. kw Q. NM oR n l O Q mm mwwm \-w z w m um km mm wm APPLICATION FILED MAR 11, I918.

Patented Jan. 13, I920.

3 SHEETS-SHEET 3- u H IH I HP I I I IH H I IUH I IH HHI I I I IHHI I IIU I I I IH Hh I IWI I IH HUnhw u H I I I I I I I I I 1 l r t WHIIIIIIHII IH "I I I I u u n HnII I IH nn "III I UNITED STATES PATENT OFFICE.

FRANK A. LuNDQuIsr, E CHICAGO, IIZYLINOISLASSIGNOR '10 CASPER L.REDEIELD,

TRUSTEE, OF CHICAGO, ILLINOIS. I

i CALLING MECHANISM EoR TELEPHONE-EXCHANGES.

' To all whom it may concern:

Be it known that I, FRANK A. LUND- oors'r, a citizen of the UnitedStates of America, and aresident of the city of Chicago; county of Cook,and State of Illinois,

ing is a specification.

My invention relates to calling mechanisms for use in automatictelephone exchanges and has for its object.the construcs tion of adevice which an operator may use continuously and rapidly and which willcause 'a minimum of inconvenience to such operator;

' The accompanying drawings showthe mechanism with inclosing case andsome connections omitted as not being necessary to an understandin ofthe invention. Also, the mechanism is s% where a diagrammatic showindescribe than a full detail 0 struction. In the said drawings.

Figure 1 is a side elevation of the mechanism with some of the keysdepressed preparatory to sending calling impulses;

Fig. 2 is an end view in the direction 2 of Fig. 1, some parts beingomitted;

Fig. 3 is a section on line 33 of Fig. 1, but with all of-the keys inelevated position;

Fig. 4 is a horizontal section on line 44 of Fig. 1;

Fig. 5 is a plan with some parts broken is easier to actual conaway withsome of the parts below in. section;

Fit. 6 is a section on line 66 of Fig. 1; Fig. 7 is an enlarged verticalsection through the valve chest; and

. Fig. 8, 9 and 10 are details.

The upper face of the calling mechanism has on it a plurality of rows ofkeys, the keys in each row being numbered from 1 to 0 inclusive, asshown in Fig. 5. In the drawings, four rows of keys are shown, and adevice having four rows of keys 1s adapted to call any number up to9999. In Figs.-

land 2, one ke in each row is shown depressed. These eys are indicatedin Fig. 5

by an extra dark border placed on this drawing for the purpose ofidentification. With these keys depressed the devlce is set for callingstationnumber 4567. In addition to the numbered keys thereis a start keywhich will .be described later.

Specification of Letters Patent. i

own in part in diagram Patented Jan.'13, 1920.

Application filed March 11, 1918. Serial No. 221,598;

The mechanism is located between a lower plate 11 and an upper plate 12.Supported on posts 13 (Fig.1) is an extra plate 14. The numbered keysare mounted on the up per ends of stems 15 guided in plates12 and 14,and are normally supported in an elevated position by springs 16.

On the plate 12 are ears or lugs 17 and pivoted to these lugs areswinging links 18. Supported on the lower ends of these links are plates19, there being one plate 19 extending longitudinally under each row ofkeys, and each plate-19 having therein a series of slotted holes for thestems 15 of its row. Springs 20 (Fig. 1) normally hold these plates 19to the left. On the stems 15 are lateral projections 21. When a plate 19is to the left, the edges of the slotted holes come under the projection21 and locks the keys against depression. Also, if a plate 19 is movedto the left after one of the eys in its row has been depressed, then theedge of the slotted hole will come over the projection 21 on thedepressed key and hold it in its depressed position. The swinging plates19 are looking plates to hold keys in either elevated or depressedposition when said plates are to'the left, but said plates leave thekeys free to move when said plates are moved to the right.

Supported between plates 11' and 12 at u opposite ends of the device arespindles 22 and 23 which carry sprocket whee1s24 and 25, and mounted onthese sprocket wheels are belts or tapes 26. There is one tape 26 foreach row of keys, and each tape has thereon a stop 27. On spindles 23and ad jacent posts 28 are springs 29 which act to rotate said spindles,and hence to move the tapes, in a direction whi h will bring the .oflockplates l9'is the unlocked position which permits the numbered keys to befreely moved up or down.

Located under each row of key stems 15 is a long bar 31 supported onlinks 33 and I05 34. The links 33 aresecured rigidly to a shaft 35,while the links 34 are loose on pins or studs. The bar 31' with itslinks forms 9 a parallel motion so that when a bar is depressed by adescending key stem it 111 remain under such stem. At one end the shaftsand adjacent pins are supported in brackets 36, while at the other endthey are shown as supported on the side of the air chest 46 to be laterdescribed.

The link 34 at the right is made laterally slidable on its pin 37, butis normally held in the position shown by a spring 38 on a part of thebar 31. On the pin 37 is an arm 39, one part of which projects laterallyun der the adjacent link 34, and a spring 40 on said pin acts to elevatesaid arm and link, and consequently the bar 31. It is to be understoodthat these parts are duplicated for each row of keys on the machine.

Located in the lower part of the machine, and associated with each tape26, is an air cylinder 41 having a piston 42, and secured to each pistonis a rack 43 adapted to engage a gear 44 on a spindle 22. The cylinderis closed by a head on the side of the piston opposite the rack, andfrom this head there is a pipe 45 extending to an air chest 46.Compressed air is conveyed to this chest, from any, suitable supply, bya pipe 47 (Fig. 4), and is represented in Fig. 7

' by the conduit 48 which runs longitudinally through the chest 46. Fromthis conduit there is a branch 49 leading to the pipe 45, and anotherbranch 50 for exhaust.

The pin 37 previously described as the support for the link 34, is, infact, the outer end of a valve for controlling the supply of air to thecorresponding cylinder 41. The inner end plugs the connection betweenthe conduit 48 and the branch 49, and has in it a transverse hole whichmatches branch 50 when the connection is closed between 48 and 49. Thearm 39 is secured to the pin 37, and when said arm is depressed as aresult of depressing one of the numbered keys on the machine, the valveis turned to open the connection between 48 and 49, and to close theexhaust 50. A screw 51 serves as a means for adjusting the exhaustopening so that the rate of exhaust may be anything desired.

The sprocket wheels 24 on spindles 22 have long teeth 52, and in thepaths of these teeth are levers 53 pivoted at 54. Springs 55 normallyhold the ends of levers 53 against projections 56 on slide 57 operau ingin a guide 58 on plate 12. .When a rack 43 operating on its ear 44 movesa sprocket wheel 24in the dlrection of the arrows shown in Figs. 4 and5,.the teeth 52 strike a lever 53 to move it away from the adjacentprojection 56. This action does not affect the position of the slide 57.But when a sprocket wheel moves in the opposite direction, the teeth 52strike the lever 54 on the sprocket side and cause a movement of theslide 56. On one end of this slide is a piece of insulation 59 whichrests against a contact spring 60, When the slide 58 is moved having apin 66 on its upper end, which pin is engaged by the cam 63 to move thelever 65 on its pivot 64 when the start key 62 is depressed. When the,start key has reached its lowest position the pin 66 catches over thecam 63 to hold the start key in its depressed position until released ashereinafter described. That part of lever 65 which is located on theopposite side of the pivot 64 ismarked 67 and engages the side ot theadjacent link when said link is in its lower position. When thedescending cam 63 engages pin 66 to move lever 65, the arm 67 01 saidlever pushes link 34 from the catch on arm 39, whereupon spring 40raises said arm 39 to turn pin 37 and thus close the air connectionbetween 48 and 49, and at the same time to open the exhaust 50.

Pivoted at 67 (Fig. 4) on the bottom of the air chest 46 is a lever 68,one'end of 'whiCh is connected by a link 70 with the pin 30 dependingfrom that look plate 19 which is on the same side of the machine as thestart key. The other end of the lever 68 has a projection 71 engagingthe next link 34 and adapted to push it from engagement with theadjacent arm 39 when the lever- 68 is moved on its pivot 67. Similarlythere are other connections of the same kind between the next pin 30 andthe next link 34,-

and the same thing is repeated until the last link 34 is reached.

Pivoted at 72 part of the frame work isa bell crank lever 73, one arm ofwhich is adjacent to the last pin 30. The other arm of the bell cranklever 73 has connected thereto a link 74 which extends across themachine and contacts the side of the flexible lever 65. When the bellcrank'lever 73 is moved on its pivot, as will be described, the link 74pushes the lever 65 to one side so that. the pin 66 is released from cam63, whereupon the start key 62 will rise under the action of the springon its stem.

In operating the device the operator will depress those keys on thekeyboard which will indicate the number to be called. It is here assumedthat the number 4567 is to be called, and the keys for that number areindicated b dark borders in Fig. 5. Upon depressing ey number 4 in thethousands 11 is a long and laterally flexible lever 65 F (Fig. 4) on aconvenient column of the keyboard, the corresponding bar 31 will bemoved downward on its links 33 and 34. As the corresponding arm 39 onpin 37 is at this time in engagement with the adjacent link 34, thisdownward movement of bar 31 results in turning the pin 37 to open theconnection between the air channel 48 and that passageway 49 which leadsto the pipe 45 connected to the correspondin air cylinder 41.

he admission of compressed air to the cylinder behind piston 42 drivesthat piston toward the opposite end of the cylinder 41 and causes theconnected rack 43 to turnits gear 44 and consequently the sprocket wheel24 on the same spindle. This movement of the sprocket wheel moves thetape 26 thereon so as to carry its stop 27 away from the associated pin30 and permit the spring 20 to move the corresponding lock plate 19 tocatch and hold the depressed key in depressed position. When the stop 27on tape 26 engages the projection 21 on the stem of the depressed keythe movement of the piston 42 under the action of the compressed air isarrested. The spacing of the teeth 52 on the sprocket wheel 24 is sorelated to the spacin of the keys on the keyboard that when ey No. 4 isdepressed four of the teeth 52 will engage and pass the correspondinglever 53. But this movement under the action of the compressed air isone which moves the lever 53 away from the corresponding projections 56and consequently produces no results.

When key No. 5 in the hundreds column of the keyboard is depressed, itmoves the corresponding bar 31 downward and results in turning thecorresponding pin 37 to admit compressed air to the corresponding aircylinder 41. The consequent movement takes the corresponding stop 27away from its pin 30 to contact with t e projection 21 on depressed keyNo. 5. In this case, five teeth 52 pass the corresponding lever 53 andset this part of the apparatus for five contact movements in the sameway that the previously described parts were set for four contactmovements.

In the same way, the depression of key No. 6 in the tens column of thekeyboard sets the corresponding parts for six contact movements, and thedepression of key No. 7 in the units column sets for seven contactmovements. In other words, the apparatus is set for any number ofcontacts in thousands, hundreds, tens or units by depressing acorrespondingly numbered key in the desired column.

Afterthe number is thus set up on the keyboard, the operator depressesthe start key 62 which first moves the lever 65 and is then caught andheld by the pin 66 thereon. Upon this movement of the lever 65, the arm67 thereon pushes the adjacent link 34 from the catch on arm 39, andpermits said arm to rise under the action of spring 40. This movementturns the pin 37 to close the connection between the air supply 48 andthe channel 49 leading to the corresponding cylinder41. The same turningof the pin 37' also opens the exhaust so that the air in the cylinder 41may flow out through channel 50 past the screw 51. As soon as the airpressure is thus relieved the spring 29 connected to the correspondingsprocket parts back toward normal position at a rate which is determinedby the adjustment of the screw 51.

In this backward movement, the teeth 52 on sprocket wheel 24 engage theassociated lever 53 to cause reciprocations of slide 57. Each movementthus given to the slide 57 pushes contact spring 60 away from contactspring 61 and breaks a circuit in the telephone exchange at this point.As soon as a tooth 52 passes a lever 53, the spring 60 acts to returnthe slide 57 to normal position and 60 again engages v61. When the stop27 on the returning tape 26 comes to the pin 30 on the lock plate 19,the force of the spring 29 overcomes that of the spring 20 with theresult that the lock plate is released from the projection 21 on key No.4 and said key rises by action of its spring 16. At the same time themove- -'ment of the-tape is arrested by reason of the fact that the lockplate 19 has only a very short movement by reason of contact between thetape-stop 27 and the pin 30.

The spacing of the teeth on the sprocket wheels 24 corresponds to thespacing of the keys on the keyboard. Thus, when a stop 27 moves backfrom a key No. 4 to contact with its related pin 30, the teeth 52 willgive four reciprocations to the slide 57 and cause four successive makeand break connections at contact 60-61. When a. stop 27 moves back froma key No. 5, there will be five make and break connections at contacts60-61. From key N o. 6 there would be six make and break connections,and so on.

The return of the thousands tape 26 causes its stop 27 to move pin 30,and connected to this pin is link 70 on lever 68. The movement of thislever causes its projection 71 to move the next link 34 so as to releaseit from its catch 39. When this, occurs the valve for the hundredscylinder 41 is opened by its spring.40 with the result that the hundredstape 26 will return to its normal position and cause its stop. 27 toengage the adjacent pin 30 and release the depressed key in the hundredscolumn of thekey board. In this return movement there will be as manyreciprocations of the slide. 57 as was indicated by the number on thedepressed'key. The completion of the return of the hundreds tapereleases, in'the' same way, the connections for the tens tape,

and the tens tape releases for the units tape. When the stop 27 on theunits tape engages its pin 30, (upper right hand portion of Fig. 4), itmoves the bell crank 73 to move link or slide74 so as to push to oneside the flexible lever 65 and release pin- 66 from the cam 63 on startkey 62. When this occurs the start key rises to its normal positionunder the action of the elevating spring on its stem.

When the key on the key board is depressed as described it moves its bar31 downward on its links 33 and 34. The links 33 are secured tothe'shaft 35, andon this shaft is a spring 75 which has one end securedto the shaft and the other end secured to the bracket 36. The depressionof the bar 31 winds this spring up, and when the key is later released,the spring acts to return the bar 31 to its normal elevated position.This occurs for each bar 31 after the corresponding arm 39 has beenreleased from its adjacent link 34 and has' risen under the action ofits sprin 40. ,In the rising of a bar 31 under t e action of its spring75, the link 34 is raised above arm 39, whereupon the spring 38 movesthis link 34 laterally to its normal position over the catch on arm 39.

What I claim is:

1. In a calling mechanism, a series of keys representing differentnumbers, a pneumatic device associated with said keys, a source of airpressure for operating the pneumatic device, means by which upondepressing a key having thereon any particular number the pneumaticdevice will set the mechanism for a number of electrical impulses whichcorrespond to the number on the depressed key, means for releasing thepneumatic de vice so that the mechanism may return to normal position,and automatically operating means for releasing, the depressed key uponthe completion of such return movement.

Y 2. In a calling mechanism, a series of keys representing differentnumbers, a pneumatic device and source of air pressure for operating it,means by which the depression of a key starts the pneumatic device intooperation and stops it at a position corresponding to the location ofthe key depressed,

means for releasing the pneumatic device,

. means for returning the moved parts to normal position when soreleased, and means operated by the return of the moved parts for makinga series of electrical contacts corresponding in number to the numberrepresented b the depressed key.

3. In a ca ling mechanism, a series of keys representing digits in'units, a second series of keys representing digits in tens,

a pneumatic device for each series, means by which the depression of akey starts the corresponding pneumatic device into op- 4. In acallingmechanism, a key board having a series of keys for units andanother series of keys for tens, a power device associated with eachseries, means by which upon the depression of a key the correspondingpower device will be started into operation for a movement correspondingin length to the location of the depressed key, manually operated meansfor releasing the parts operated by one of the power devices, a springfor returning the moved parts to normal position, and means operated bythe return of the parts moved by one power device for automaticallyreleasing the parts operated by the other power device.

5. In a calling mechanism, a contact making device, independent powerdevices for units, tens and hundreds, a series of keys each for units,tens and hundreds, means by which upon depressing a key in any seriesthe corresponding power device will be operated to an extent determinedby the key depressed, a start device for releasing the parts moved byone of the power devices, restoring means by which released parts arereturned to normal position, and automatically operated means controlledby returning parts for releasing other parts so that they may also berestored to normal position.

6. In a calling mechanism, a device movable from normal position by airpressure, a series of keys arranged in a row and each key serving whendepressed as means for stopping the moved device a difl'erent distion, aseries of keys each one of which serves when depressed to start .onepower device to move the body from normal position and to arrest suchmovement at a different point, locking mechanism for holding a depressedkey in depressed position, manually operated means for causing the otherpower device to return the moved body to normal position, electricalcontacts operated in depressed position and the other keys in eachseries of keys, a contact operating dethe same series will be lockedagainst depression, an independent powerdevice for vice associated witheach power device,

means by which upon depressing one key in each series the mechanism willbe set for calling a number corresponding to the keys depressed, amanually operated start device, and automatically operatin means bywhich upon operating said start evice the contact operating devices willbe operated a number of times which corresponds to the number for whichthe mechanism was previously set.

9; In a calling mechanism, a separate series of keys for the digits inunits, in tens, in hundreds and thousands; a separate locking device foreach series arranged to prevent the depression of more than one key in aseries; separate power mechanism for each series of keys; a contactmaking device; and means by which upon starting one power mechanism intooperation the others will follow automatically in succession and willoperate the contact making device the number of times indicated byprevious depressed keys in the different series of keys.

10. In a calling mechanism, a series of cylinders each having a pistonand connect1ons by which the pistonis moved in the cylinder, a series ofnumbered keys associated with each cylinder, means by which upondepressing any key the corresponding piston will be moved automaticallya distance represented by the number on the depressedkey, a contactmaking device operable by movement of each piston a start devicearranged to be operated after one key in each series has been depressed,and means by which upon operating saidstart device the pistons willautomatically return in succession to their original positions and in soreturning will operate the contact making device the number of timesindi-' cated by the depressed keys.

11. In a calling device, a movable tape or belt having a stop securedthereon, a series of keys each of which is movable to a position in thepath of said stop, means by which upon depressing a key the tape will bestarted to move and will be arrested by the stop engaging the depressedkey, automatic means for returning'the stop to its original position,and a contact making device operated by such return movement.

12. In a calling device, a cylinder and piston, a valve for admittingair to the cylinder to move the piston, a series of keys each one ofwhich when depressed serves to operate said valve, means associated withthe keys for stopping the movement of the piston at a different positionfor each key, separate means for reversing the valve so as to permit thepiston to return to normal position, and a contact making deviceoperated by such return movement.

FRANK A. LUNDQUIST.

